Well packer



Patented Sept. 28, 1943 WELL mom-1n Reuben C. Baker, Coalinga, Calif.,assignor to Baker Oil Tools, Inc., Vernon, Calif., a corpora tion ofCalifornia Application September 22, 1941, Serial No. 411,802

Claims.

This invention relates to well packers, and more particularly to packingdevices forming a part thereof for efiecting a seal with the wall of awell casing 01 other confining enclosure;

The present application is a continuation-inpart of my applicationentitled Well packer apparatus, Serial No. 333,491, filed May 6, 1940,now Patent No. 2,275,935.

It is an object of the present invention to provide a well packerembodying a packing member which is held positively in sealingengagement with the wall of a confining enclosure, and in which the sealefiected with such enclosure is of more uniform character around theperiphery of the enclosure than was heretofore obtainable.

Still another object of the invention is to provide an improved packingconstruction in a well packer of such character as to be capable ofslidable leak proof movement on the supporting body of the packer withlesser resistance.

This invention has other objects that will become apparent from aconsideration of the embodiment shown in the drawing accompanying andforming part of the present specification. This form will now bedescribed in detail, but it is to be understood that such detaileddescription is not to be taken in a limited sense, since the scope ofthe invention is best defined by the claims appended hereto.

Referring to the drawing:

Figure 1 is a partial sectional and partial elevational view of part ofa well packer embodying the present invention, with the packing memberthereof disclosed in retracted position;

Figure 2 is a view similar to Figure 1, with the packing memberdisclosed in expanded position;

Figure 3 is a longitudinal section through the packing member per se;and

Figure 4 is a plane view of the packing member as seen from the bottomof Figure 3.

In the drawing, the invention is disclosed as forming part of a wellpacker mechanism particularly described in the patent to Reuben C. Bakeret al., Patent No. 2,225,143, granted December 17, 1940, on Well packermechanisms. This packer includes a generally tubular body III having aguide II threaded on its end. Also threadedly attached to the body is aconical expander I2 adapted to positively expand a cupshap d packing I3against the wall of a casing I4, and to hold it positively in expandedposition thereagainst.

One end of this cup-shaped packing I3 is secured to a packing retainerI5 slidable on the body I0. This retainer includes an inner sleeve I6extending from its base portion I1, and an outer skirt I8 extending fromits base portion and provided with an inwardly extending flange I9. Theskirt I8 and sleeve I6 are spaced from each other to form a circulargroove in which the fixed end of the cup-shaped packing I3 ispositioned. This packing includes a base portion 2| abutting the end ofthe retainer skirt I8, with its inner surface snugly engaging the outerperiphery of the retainer sleeve I6. Extending longitudinally outwardlyfrom this base portion is a locking portion of the packing, consistingof a ring 22 having an outwardly directed flange 23, received within thecircular groove 20 formed between the retainer sleeve I8 and skirt I8.The inwardly directed skirt flange I9 and outwardly directed packingflange 23 interlock to secure the packing I3 in the packing retainer I5.

While in retracted position, the free end 24 of the packing ispreferably protected by an encompassing circular lip or ring 25extending from the guide II. The free end of the packing is adapted tocooperate with the conical expander I2 to be forced thereby outwardlyinto contact with the casing I4. To accomplish this purpose, the freeend 24 of the packing is provided with a plurality of inwardly directedand circumferentially adjacent fingers 2B capable of engaging thetapered surface of the conical expander to expand the end 24 of thepacking outwardly against the casing. Such engagement and movement alongthe conical expander I2 toward its larger end takes place under theimpetus of a helical spring 21 positioned within the conical expander.One end of the spring engages the base of this expander I2, while itsother end engages the retainer sleeve l6.

As disclosed in Figure l, the helical spring 21 as held in contractedposition, with the cupshaped packing I3 retracted and its free end 24within the confines of the lip 25. The spring is prevented fromexpanding by any suitable means, such as a latching mechanism (notshown) acting directly upon the packing retainer I5 to prevent itsmovement along the body I0. Particulars of the latching mechanism arenot essential to an understanding of the present invention, and may befound in the patent above referred to. It is suflicient to state thatthis latching mechanism prevents movement of the packing retainer I5under the action of the spring 21, but when this mechanism is released,the spring may expand to move the packing retainer I5 and packing I3along the body I0 and shift the inwardly directed fingers 26 along theconical expander I2 to force the free end 24 of the packing against thewall of the confining enclosure I4, as is represented in Figure 2.

The engagement of the packing with the casing prevents fluid frompassing therebetween. Leakage between the packing retainer I5 and thebody III of the packer is prevented by a seal ring 28 situated within aninner groove 29 in the sleeve I 6, and provided with a lip 30 engagingthe exterior of the body. The pressure from within the cup packing I3acts upon this seal lie.

ring and its lip to force and hold it in engagement with the body i0,thus preventing leakage therealong. As a result, it is evident thatfluid is prevented from passing between the body l and easing I 4through the sealing actions of the i cup-shaped packing [3 against thecasing and of the seal ring 28 against the body.

Because of the manner of mounting the packing l3 in the retainer i5,very little resistance is encountered to sliding movement of theretainer and packing along the tool body l0 under the influence of thehelical spring 21. The seal ring 28 is effective to prevent leakagebetween the retainer sleeve i6 and body without creating sumcientfriction to materially impede movement of the retainer. The cast iron orother comparatively rigid material of which this packing retainer may beconstructed produces very little friction against the cast iron or othermetallic material of the packer body l0. Substantially the full force ofthe helical spring 21 is therefore available for expanding andholdingthe free end 24 of the packing against the wall of the casing.This is a better arrangement than the one disclosed in theabove-mentioned patent, in which the base of the packing itself engagesthe packer body, creating a great amount of friction and resistance tomovement of the packing along the body with respect to the conicalexpander.

The employment of the inwardly directed fingers 26 which are preferablymolded as an integral part of the packing so as to be separated from oneanother by slots 3| extending to the skirt 32 of the packing, enablesthe free end 24 of the packing to expand orbe stretched outwardly withgreater facility to the increased diameter disclosed in Figure 2. If,instead of employing the separated fingers 28, a continuous inwardlydirected flange were used, a much greater resistance to outwardexpansion of the free end of the packing would beencountered. Thefingers can separate readily and will enable outward expansion of thefree end of the packing to take place without undue restraint.

Although the use of the inwardly directed fingers 26 possesses theabove-noted advantage, it is sometimes noted that the free end 24 of thepacking fails to make a uniform sealing contact with the wall of thecasing. The contact is apparently intermittent in character. Efl'ectivesealing engagement occurs at the fingers 26, but the packing materialbetween the fingers is sometimes spaced from the casing, offeringregions through which fluid may leak. The spaced, inwardly directedfingers therefore might produce a corrugated or rippled surface on theexterior of the packing.

For the purpose of guarding against the occasional occurrence of thisrippled effect, an outwardly directed packin lip 33 is formed onthe freeend 24 of the packing. This lip is separated from the fingers 26 by agenerally V-shaped groove 34 and preferably extends outwardly beyond thetransverse plane in which the fingers As a result of this construction,the greater pressure exerted by the fingers 26 against the packing end24 and casing over that existing in the packing between the fingers hasno effect upon the packing lip 33 due to the separation mentioned. Uponexpansion of the packing, the lip 33 engages the wall of the casinguniformly around its entire circumference. Following the engagement ofthe packing lip with the casing, pressure in the casing acts within thepacking to expand it against the casing over a greater poruniform sealdesired.

It is therefore apparent that a well packer has been provided embodyinga packing device which is readily movable along the supporting packerbody, and which eflects an efficient seal with the wall of a confiningenclosure.

Iclaim:

1. A cup-shaped packing adapted to be expanded laterally outwardly by aconical expander, said packing comprising a plurality of inwardlydirected fingers arranged circumferentially adjacent one another aroundthe interior of said packing at its free end, said fingers lying in aplane substantially at right angles to the axis of the packing forengagement with the tapered surface of said expander to expand said freeend of the packing laterally outwardly.

2. A packing adapted to be moved into sealing engagement with a memberby an expander, said packing comprising a plurality of juxtaposedseparated fingers engageable with the tapered surface of said expanderto force said packing laterally into sealing engagement with saidmemher, said packing also including an annular lip adapted to make auniform circumferential seal with said member whose uniformity issubstantially unaffected by said fingers.

3. A packing adapted to be moved into sealing engagement with anenclosure by a conical expander, said packingcomprising a plurality ofinwardly directed fingers arranged circumferentially in juxtapositionaround the interior-of said packing and engageable with the taperedsurface of said expander to expand said packing laterally outwardly,said packing also including an annular lip spaced from said fingers soas to make a uniform circumferential seal with said enclosure whoseuniformity is substantially unaffected by said fingers.

4. A cup-shaped packing adapted to be moved laterally outwardly by aconical expander, said packing having a plurality of inwardly directedfingers arranged circumferentially adjacent one another aroundthe-interior of said packing at its free end, said fingers lying in aplane substantially at right angles to the axis of the packing forengagement with the tapered surface of said expander to expand said freeend of the packing laterally outwardly, the free end of said packingalso including a lip spaced from said fingers to define acircumferential groove therebetween.

5. A cup-shaped packing adapted to be moved laterally outwardly by aconical expander, said packing having a plurality of inwardly directedfingers arranged circumferentially adjacent one another around theinterior of said packing at its free end, said fingers lying in a planesubstantially at right angles to the axis of the packing for engagementwith the tapered surface of said expander to-expand said free end of thepacking laterally outwardly, the free'end of said packing also includinga terminal circumferential lip extending longitudinally from the planeof said fingers.

REUBEN C. BAKER.

